Baseline, New Manifold, New RockersIt took a little bit longer than we'd expected, but Danger Mouse (DM) is officially open for business. If you're not familiar with this engine project, here's some background: Last year we introduced the idea of building a test engine and taking suggestions from our readers as to what they would like to see tested. The initial response was good but tapered off quickly as we had to push DM to the back burner and tackle other projects first. This year, we vowed to make DM a reality. Last month, we showed you the short-block buildup, highlighting the strong bottom end components from Lunati and World Products, and this month we'll finish it off with the top-end assembly and the first round of dyno bashing. This has quickly become one of the coolest engine projects we've ever done. Not only will DM now be able to provide SUPER CHEVY readers with their very own dyno engine, but it's already surpassed our initial power expectations on its very first outing!

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We wanted to begin testing with a set of factory cast-iron heads. But we didn't want to handicap Danger Mouse with them, so we ordered a set of rebuilt 461 "camel humps" from Powerhouse Engine Components.

When we took DM over to the Westech Performance Group for its initial flogging on their SuperFlow 901 dyno, we anticipated a rather dull day. That's because, at the time, DM was only equipped with a donated cast-iron, spread-bore intake manifold from the students in Burbank High School's auto shop class, and a set of stock cast-iron GM heads, commonly referred to as "Camel Humps" (casting No. 461). Powerhouse Engine Components rebuilt the heads for us using replacement stainless steel (1.94/1.50) valves and high-performance single-coil valve springs with a damper. Powerhouse also machined the heads for screw-in rocker arm studs and installed pushrod guideplates but did no porting or polishing. Even with a cam that most would consider too small to really make some power, this engine still cranked out over 300 hp in its most basic form.

After some basic ignition advance adjustments, no other changes were required to make this little mule kick. The Carb Shop Q-Jet worked fantastic right out of the box and only required a metering rod adjustment to lean it out slightly after we installed the Weiand intake manifold and the motor started pulling a little more air. Danger Mouse worked so well, in fact, that even the dyno operators at Westech were impressed with how much power it made in stock form. Three hundred ponies from a stock-headed Mouse with a factory intake is something to admire. It's the result of a good engine blueprint and the selection of the right cam for the application. Soon, we'll try some other cams to see just how big we can go before the stock heads become a limiting factor. Then we'll swap heads and go for the gusto. If you can think of anything you'd like to see tested on Danger Mouse, feel free to write us a letter or email it to the address listed above. Remember, this is your test engine and we want to hear your ideas, otherwise we'll be left to come up with our own and that would hardly be any fun.

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Small-Block Chevy Test Engine - Danger Mouse Part Two

We wanted to begin testing with a set of factory cast-iron heads. But we didn't want to handicap Danger Mouse with them, so we ordered a set of rebuilt 461 "camel humps" from Powerhouse Engine Components.

To keep it real, we installed Comp Cams Pure Energy hydraulic camshaft. It's one of the smallest grinds Comp has and is 50-state emissions legal. It had a cool idle around 600 rpm that sounded neither docile nor radical. It also made 20 inches of vacuum.

Powerhouse upgraded the 461 GM castings with new valve springs and new 1.94/1.50 stainless valves. The heads were milled to a 62cc chamber volume, which puts DM right at 9.4:1. That's too high for 87-octane gas, so we ran all tests on 92-octane premium 76 Performance unleaded.

We finished the top end off with 1.5:1 stamped-steel replacement rocker arms from Comp Cams to make sure rocker ratio would not be an issue. SCE supplied a complete gasket set to seal DM up tight.

A new HEI distributor from Proform gives DM a hot spark. Champion No.14 plugs were used to light the fire.

To keep things consistent we used 76 Racing motor oil and fuel for all tests.

The first bolt-on was a Weiand Action Plus intake manifold (PN 8004). It worked very well, adding 17 hp over the stock cast-iron manifold. Not bad for less than $100.

The Carb Shop Q-Jet worked flawlessly until we bolted on the Weiand intake and the engine started breathing better. We had to lean the carb out just a bit with larger metering rods because it pulled more fuel and ran richer with the new intake.

We bolted on set of Comp Cams 1.5:1 roller-tip rocker arms and got 17 more ponies. DM was now making 34 more horsepower with just an intake, jetting, and roller-tip rockers. That's an 11 percent power increase with two simple bolt-ons.

Comp Cams also supplied the beltdrive we'll use for most of the tests because cam timing adjustments and swaps are easiest with it. The trick to tightening the cam hub on a beltdrive is to use a long screwdriver to keep the cam from rotating as you tighten the bolts.

It's always important to degree the cam correctly. We installed the cam at Comp's recommended 106-degree intake lobe centerline, which is technically "straight up."

Before closing up the bottom end, we installed the Milodon high-volume oil pump and pickup tube. It's wise to lock the oil pump cover plate screws in place using some high-strength thread-locking compound after you've pressed in the pickup tube.

To seal the oil pan and make repeated removals easier SCE supplied its one-piece oil pan gasket, which is a breeze to install. It's a good idea to add a little silicone to the four corners around the front and rear main caps to prevent leaks.

Milodon supplies the kick-out-style oil pan we used with or without a windage screen. For the first test we chose the pan without a windage screen so we can later find out how much power windage takes away.

We chose Milodon's head studs over bolts because we know we'll be swapping heads often, and studs are a better way to keep the threads in the block in good shape.

When we built Danger Mouse (DM) more than a year ago, we wanted to have an engine in our stable that we could use to test and re-test every possible power combination we could think of. After more than 1,000 dyno pulls, we think we've found a few new recipes for perfection. » Read More